ArduCopter 2.5 released!

Version 2.5 of the ArduCopter code is now available in the AP Mission Planner and in the downloads area!

Enhancements:

The first ArduCopter code release optimized for the APM 2. Leans and drift should be much reduced or even eliminated for most users. This was accomplished through a number of core improvements to the DCM implementation by Tridge like this one and this one.

Loiter and waypoint following should be improved due to a D term bug fix, some tuning and the improved DCM performance mentioned above.

On start-up, the yaw heading is updated with first successful mag read (so you should no longer see the slow rotation from north to your actual heading).

The default PIDs are optimized for a 3DR/Jdrones quad with 850 motors and 10" props. If you're using more powerful motors/props, start by turning down Rate Roll P in 25% steps.

While some testers have reported very good flights with the default PIDs, some have reported that this release is a little "sharper" due to the DCM improvements and have found they needed to:

reduce stabilize P by 10% (i.e. 4.5 -> 4.2)

reduce stabilize D by 30% (i.e. 0.15 -> 0.10)

increase rate D from 0 to 0.001

Tuning loiter can be tricky. Refer to the discussions which will appear below for more community feedback on what parameters work best.

Please post your feedback in this discussion. For enhancement requests and bug report, please add them to the arducopter issues list. When possible please include logs (tlog and/or dataflash) and tell us whether you're using APM1 or APM2 and what version of the software you're using (presumably 2.5 but tell us anyway!).

Thanks for this release go to the developers (both in the core team but also those who have provided bug fixes through the issues list) and also the community members who participated in the previous release thread and provided some great detailed information in the form of issue reports and logs which allowed us to nail some bugs!

So for any of you flying the latest official code, mind posting more param files and observations? I am having difficulties with altitude hold and loiter currently with my setup. Flying in moderate winds also is a bit hairy. I don't consider my setup dialed in, especially since I have payload intergration development going on. However, in a low wind enviroment, the quad is pretty stable.

BTW, anyone flying with Stab_I terms greater than 0? I vaguely remember seeing advice not using the Stab_I with the PIDT1 control scheme, but I am not sure if we are currently using that control loop setup right now.

heya fellas, just out on the field and tried the new code on my hexa. running apm 1 1250, crash bang all i can say. sorry, yaw seems to be the culprit here, gets stuck again and you very quickly lose orientation. just broke 1 prop but i tried many times and done a compass recalibration too. is this yaw "stuck" issue prominent on hexa's only or throughout all configurations including quads?

I finally loaded 2.5.3 onto my 8X Quad after doing full CI erase and reset and recalibrate everything . On some checking the sonar is not working and even if I hold it up to 2 meters it never reads more than 32cm. Any ideas why?

Also where can I find instructions how to use the compass declination calibration that's now new on MP? For now I just added my usual declination. Is this ok?

I have adjusted just the few of my PIDs to the setting I normally use.